$(function (){
    var show_num = [];
        draw(show_num);
        $("#canvas").on('click',function(){
            draw(show_num);
        })
    //点击更换验证码图片
    // $(".changeImg").click(function (){
    //     $(".changeImg").attr("src", baseUrl +"/news/img/captcha-image"+"?a="+Math.random());
    // })
    // $(".Sign_in").click(function (){
    //     window.location.href="./index.html";
    // })
    //登录
    $(".Sign_in").click(function (){
        var val = $(".yzm").val().toLowerCase();
            var num = show_num.join("");
            if(val==''){
                alert('请输入验证码');
                return false;
            }else if(val == num){
            }else{
                alert('验证码错误！请重新输入！');
                return false;
            }
            if($(".user").val()==""){
                alert("请输入用户名")
                return false;
            }
            if($(".pass").val()==""){
                alert("请输入密码")
                return false;
            }
        var json = {
            username:$(".user").val(),
            password:$(".pass").val(),
            captcha: $(".yzm").val()
        }
		var result = JSON.stringify(json);
        $.ajax({
            url: baseNews + "/bg/sys/doLogin",
            type:"post",
            headers: { 'Content-Type': 'application/json' },
            dataType: "json",
            data:result,
            success:function (res){
                console.log(res);
                if(res.code==0){
                    localStorage.setItem("uToken",res.data);
                    location.href="./index.html";
                }else{
                    alert(res.message);
                }
            }
        })
    })
})

//生成并渲染出验证码图形
function draw(show_num) {
    var canvas_width=$('#canvas').width();
    var canvas_height=$('#canvas').height();
    var canvas = document.getElementById("canvas");//获取到canvas的对象，演员
    var context = canvas.getContext("2d");//获取到canvas画图的环境，演员表演的舞台
    canvas.width = canvas_width;
    canvas.height = canvas_height;
    var sCode = "a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,A,B,C,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,W,X,Y,Z,1,2,3,4,5,6,7,8,9,0";
    var aCode = sCode.split(",");
    var aLength = aCode.length;//获取到数组的长度
    
    for (var i = 0; i < 4; i++) {  //这里的for循环可以控制验证码位数（如果想显示6位数，4改成6即可）
        var j = Math.floor(Math.random() * aLength);//获取到随机的索引值
        // var deg = Math.random() * 30 * Math.PI / 180;//产生0~30之间的随机弧度
        var deg = Math.random() - 0.5; //产生一个随机弧度
        var txt = aCode[j];//得到随机的一个内容
        show_num[i] = txt.toLowerCase();
        var x = 10 + i * 20;//文字在canvas上的x坐标
        var y = 20 + Math.random() * 8;//文字在canvas上的y坐标
        context.font = "bold 23px 微软雅黑";

        context.translate(x, y);
        context.rotate(deg);

        context.fillStyle = randomColor();
        context.fillText(txt, 0, 0);

        context.rotate(-deg);
        context.translate(-x, -y);
    }
    for (var i = 0; i <= 5; i++) { //验证码上显示线条
        context.strokeStyle = randomColor();
        context.beginPath();
        context.moveTo(Math.random() * canvas_width, Math.random() * canvas_height);
        context.lineTo(Math.random() * canvas_width, Math.random() * canvas_height);
        context.stroke();
    }
    for (var i = 0; i <= 30; i++) { //验证码上显示小点
        context.strokeStyle = randomColor();
        context.beginPath();
        var x = Math.random() * canvas_width;
        var y = Math.random() * canvas_height;
        context.moveTo(x, y);
        context.lineTo(x + 1, y + 1);
        context.stroke();
    }
}

//得到随机的颜色值
function randomColor() {
    var r = Math.floor(Math.random() * 256);
    var g = Math.floor(Math.random() * 256);
    var b = Math.floor(Math.random() * 256);
    return "rgb(" + r + "," + g + "," + b + ")";
}